Automatic needle guard

ABSTRACT

A device for selectively protecting a needle includes an adapter holding the needle and a guard engaging the adapter for relative movement therebetween. Further, the device includes a means for guiding movement between the adapter and the guard. Structurally, the guiding means includes a “V” shaped slot in the guard and a radially-extending boss on the adapter. The boss is received in the slot to limit relative movement between the guard and the adapter. Specifically, in a first position of the device, the boss is in a first leg of the slot and the needle partially extends beyond the guard. In a second position, the boss is held at the apex of the slot and the needle fully extends beyond the guard. In a third position, the boss is in the second leg of the slot and the needle is retracted into the guard to protect the needle.

REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 13/273,545, filed Oct. 14, 2011, which is a continuation ofU.S. patent application Ser. No. 11/267,830, now U.S. Pat. No.8,062,265, filed Nov. 4, 2005, and hereby incorporates the sameapplications herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention pertains generally to needle protection devices.More particularly, the present invention pertains to needle protectiondevices that use a cylindrical guard to extend beyond the needle's tipto prevent contact with the tip. The present invention is particularly,but not exclusively useful as a needle protection device that usescooperation between a “V” shaped slot and a radially-extending boss tolimit relative movement between the guard and the needle.

BACKGROUND

Needles are very common in medical practices, and are frequently used todeliver medications or to draw blood for diagnosis. As a result of theirintensive use, it is estimated that some 600,000 to 800,000 accidentalneedle stick injuries occur every year. Further, there are roughly8,000,000 healthcare workers in the United States who are at risk ofbeing stuck with a contaminated needle. As the risks involved inproviding medical treatment have risen and individual safety andsanitation are taken into consideration, disposable or single-use typeof injection devices have become prevalent. While safer than reusableinjection devices, these needles must still be handled carefully and theneedle tips must be covered before and after use.

Although currently there exist various needle protection devices, mostrequire the user to take an affirmative step to cover the needle tipafter its use, thereby causing potential risk of contact with theneedle. Other devices require specially designed needles, plungers, ormedicament chambers.

In light of the above, it is an object of the present invention toprovide a protective device that can be installed on a needle to ensurethere is only a single use of the needle. It is another object of thepresent invention to provide a protective device having a guard thatpassively covers and protects the needle after an injection. It isanother object of the present invention to provide a protective devicethat controls movement of the guard relative to the needle. Stillanother object of the present invention is to provide a protectivedevice that requires an affirmative step to uncover the needle, butautomatically covers the needle after an injection. Yet another objectof the present invention is to provide a protective device for a needlethat is relatively easy to manufacture, reliable and easy to use, and iscomparatively cost effective.

SUMMARY

In accordance with the present invention, a needle protection deviceincludes an adapter for holding a needle. The device also includes aguard having a cylindrical wall that is dimensioned to engage theadapter for relative axial movement therebetween. Such movement isbiased by a spring that urges the guard away from the adapter. Further,the guard includes an orifice for selectively passing the needletherethrough. In order to guide relative movement between the adapterand the guard, the guard is provided with a “V” shaped slot having afirst leg and a second leg with an apex therebetween. Correspondingly,the adapter is provided with a radially-extending boss. The boss isreceived within the slot to limit relative movement between the guardand the adapter.

As a result of cooperation between the slot and the boss mentionedabove, the device is only moveable from a first position to a secondposition, and from the second position to a third position. In the firstposition, the boss is in the first leg of the slot and the needlepartially extends through the orifice of the guard. In the secondposition, the needle fully extends through the orifice of the guard andthe boss is held at the apex of the slot in response to a force opposingthe biasing means. In the third position, the boss is in the second legof the slot and the needle is retracted into the guard to protect theneedle.

For the purposes of the present invention, the boss is provided with anengagement face that is designed to interact with the slot to ensurethat the boss moves to the end of the second leg from the apex duringmovement of the guard from the second position to the third position.Specifically, the face is inclined toward the second leg, so thatcontact between the face on the boss and the edge of the slot causes theboss to move toward the end of the second leg.

In order to protect the needle before use, the device may furtherinclude a removable shield. Structurally, the shield includes a hollowportion for receiving the needle. Further, the shield includes aradially extending rib that can be selectively positioned in the orificeof the guard to prevent axial movement of the guard from the firstposition to the second position.

For the present invention, the device may further include a lockingmechanism that locks the device in the third position, to therebyprevent further relative movement between the guard and the adapter.Specifically, the adapter is provided with a shoulder that extendsradially outward, and the guard is provided with an abutment thatextends radially inward. When the device moves into the third position,the shoulder and the abutment engage one another to prevent furtherrelative movement between the guard and the adapter.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself,both as to its structure and its operation, will be best understood fromthe accompanying drawings, taken in conjunction with the accompanyingdescription, in which similar reference characters refer to similarparts, and in which:

FIG. 1A is a perspective view of a needle protection device of thepresent invention;

FIG. 1B is a perspective view of the guard shown in FIG. 1A,illustrating the movement of the boss in the “V” shaped slot;

FIG. 2A is a cross section view of the needle protection device of FIG.1A, as seen along line 2-2 in FIG. 1 B;

FIG. 2B is a cross section view of the needle protection device of FIG.2A with the removable shield rotated for removal in accordance with thepresent invention;

FIG. 3 is a cross section view of the needle protection device of FIG.2B, as seen along line 3-3 in FIG. 1B, with the shield removed and theneedle inserted into a subject in accordance with the present invention;

FIG. 4A is a cross section view of the needle protection device of FIG.3, as seen along line 4-4 in FIG. 1B, with the needle withdrawn from thesubject and the guard advanced to cover the needle tip in accordancewith the present invention;

FIG. 4B is a cross section view of the needle protection device of FIG.4A, as seen from a view taken ninety degrees from the view in FIG. 4A;and

FIG. 5 is a side view of the slot and boss arrangement showing theconfiguration of the slot and the boss in the first, second and thirdpositions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIG. 1A, a needle protection device in accordancewith the present invention is shown and generally designated 10. Asshown, the device 10 covers a needle 12 (shown in phantom) to preventinadvertent contact with the needle tip 14. For discussion of thepresent invention, the needle 12 defines an axis 16, a proximaldirection 15 and a distal direction 17. Structurally, the device 10includes a guard 18 having a cylindrical wall 20 that slidingly engagesan adapter 22. Further, the wall 20 includes a radially extending “V”shaped slot 24 that corresponds with and receives a boss 26 that extendsradially outward from the adapter 22. The slot 24 includes a first leg28 which meets a longer second leg 30 at an apex 32. As shown, the boss26 is positioned in the first leg 28 of the slot 24. For the purposes ofthe present invention, the slot 24 and boss 26 cooperate to guide axialmovement of the guard 18 relative to the adapter 22.

Still referring to FIG. 1A, the guard 18 is shown as including anaxially extending orifice 34 that is formed with a long axis 36 and ashort axis 38. In addition to the guard 18 and the adapter 22, thedevice 10 includes a removable shield 40. In FIG. 1A, the shield 40 isshown passing through the orifice 34 and including radially extendinggrips 42 to facilitate rotation of the shield 40 about the axis 16 asdiscussed below. As shown, the device 10 further includes a spring 44that biases the guard 18 away from the adapter 22.

Referring to FIG. 1B, the boss 26′ is positioned in the first leg 28 ofthe slot 24 (i.e., the first position of the device 10), the boss 26″ ispositioned at the apex 32 of the slot 24 (i.e., the second position ofthe device 10), and the boss 26″ is positioned in the second leg 30 ofthe slot 24 (i.e., the third position of the device 10). As can beunderstood from cross-referencing FIG. 1A with FIG. 1B, movement of theboss 26 between these positions results in rotational movement of theguard 18 about the axis 16 relative to the adapter 22, particularlyduring movement from boss 26′ to boss 26″.

Referring now to FIGS. 2A and 2B, internal components and features ofthe device 10 can be seen. As shown, the adapter 22 includes anaxially-extending and substantially cylindrical base member 46 centeredabout the axis 16. Further, the adapter 22 includes a radially-extendingcap member 48. As shown, the adapter 22 has an external surface 50 andan internal surface 52, with the internal surface 52 defining aninternal cavity 54. As further shown, the needle 12 passes through anaperture 56 formed in the cap member 48.

Turning to the guard 18, it can be seen from FIGS. 2A and 2B, that thecylindrical wall 20 includes an outer side 58 and an inner side 60. Asshown, the inner side 60 defines a chamber 62 in which the adapter 22 ispartially received. The chamber 62 is further bounded by an end member64 mounted to the cylindrical wall 20 and forming the orifice 34. Forthe purposes of the invention, the spring 44 is positioned in thechamber 62 between the cap member 48 of the adapter 22 and the endmember 64 of the guard 18 to bias the guard 18 axially away from theadapter 22.

As further shown in FIGS. 2A and 2B, the device 10 includes a removableshield 40 having a hollow portion 66 for receiving the needle 12. Asshown in FIG. 2A, the shield 40 includes radially extending ribs 68 thatare engaged with the guard 18 and the adapter 22. In the orientation ofFIG. 2A, the ribs 68 prevent axial movement of the guard 18 toward theadapter 22. Cross-referencing FIG. 2A with FIG. 2B, it can be seen thatthe ribs 68 may be removed from contact with the guard 18. Specifically,FIG. 2B depicts the shield 40 of FIG. 2A after the shield 40 has beenrotated ninety degrees about the axis 16. As a result, the ribs 68 arealigned with the long axis 36 of the orifice 34 (see FIG. 1A) and theshield 40 may be removed from the device 10.

Typically, the device 10 is stored and transported in the orientationshown in FIG. 2A. Before the needle 12 is used for an injection, theshield 40 is rotated as in FIG. 2B and is removed. Regardless of theposition of the shield 40, each of FIGS. 1A, 2A and 2 B depict thedevice in a first position 70 in which the boss 26 is received withinthe first leg 28 of the slot 24. After the shield 40 is removed, theguard 18 may be moved in the proximal direction 15 toward the adapter 22if a sufficient force is applied thereto. Specifically, if a forcegreater than the biasing force of the spring 44 is applied.

In FIG. 3, the result of an application of such a force is shown. Asshown, the needle 12 has been injected into a subject 72. As a result,the force of the subject 72 on the guard 18 has caused the guard 18 tomove toward the adapter 22. Specifically, the device 10 has moved to thesecond position 74 in which the boss 26 is positioned at the apex 32 ofthe slot 24. When the boss 26 reaches the apex 32, further movement ofthe guard 18 toward the adapter 22 is prevented by the interactionbetween the slot 24 and the boss 26.

After the needle 12 has injected a fluid 76 into the subject 72, theneedle 12 is withdrawn from the subject 72. During withdrawal, thespring 44 pushes the guard 18 away from the adapter 22. At the sametime, the boss 26 moves from the apex 32 to the second leg 30 (as shownin FIG. 4A).

To ensure that the boss 26 moves to the end of the second leg 30 ratherthan back to the first leg 28, the boss 26 is provided with anengagement face 78. The face 78 is inclined toward the second leg 30 sothat when the boss 26 moves out of the apex 32 it slides to the end ofthe second leg 30.

Referring now to FIG. 4A, the device 10 is shown in its third position80 with the boss 26 in the second leg 30. As shown, the guard 18 isextended and fully covers the needle tip 14. In order to prevent anyfurther use of the needle 12, the device 10 is provided with the lockingmechanism 82 seen in FIG. 4B. FIG. 4B is a cross section view of thedevice 10 taken from a view ninety degrees from the view in FIG. 4A.Approximately ninety degrees from the bosses 26 shown in FIG. 4A are twoshoulders 84 shown in FIG. 4B that extend radially outward from theadapter 22. As further seen in FIG. 4B, the device 10 includes twocorresponding abutments 86 that extend radially inward from the guard18. As shown, the shoulders 84 and abutments 86 are tapered. Thisconstruction allows the shoulders 84 to slide in the proximal direction15 along the inner side 60 of the guard 18 until they pass the abutments86. Once the shoulders 84 pass the abutments 86, the guard 18 can nolonger be moved toward the adapter 22. As a result, the device 10 islocked with the needle 12 protected by the guard 18.

Referring now to FIG. 5, the interaction between the slot 24 and theboss 26 can be clearly shown. In FIG. 5, the boss 26 is shown in thevarious stations (indicated by 26′, 26″, and 26′″) it passes throughduring operation of the device 10. Specifically, the boss 26′ is shownin the first leg 28 adjacent the first stop 88 when the device 10 is inthe first position 70. The first stop 88 may serve to prevent axialmovement of the guard 18 away from the adapter 22. As noted above, theshield 40 prevents axial movement of the guard 18 toward the adapter 22when the ribs 68 are positioned between the guard 18 and adapter 22.When the ribs 68 are disengaged from the guard 18 and the shield 40 hasbeen removed, the spring 44 retains the boss 26′ in the first leg 28.

When a force is applied to the guard 18 in the proximal direction 15 tomove the guard 18 toward the adapter 22, i.e., during an injection, theboss 26′ moves from the first stop 88 to its position as boss 26″ at theapex 32. Movement of the guard 18 toward the adapter 22 may be stoppedby contact between the boss 26″ and the apex 32, or by contact betweenother components in the device 10.

When the force in the proximal direction 15 is removed, i.e., duringwithdrawal of the needle 12 from the subject 72, the spring 44 forcesthe guard 18 away from the adapter 22 in the distal direction 17. As aresult, the boss 26″ moves axially away from the apex 32 to its positionat boss 26′″ in the second leg 30 of the slot 24. As indicated by FIG.5, during movement from boss 26″ to boss 26′″, the engagement face 78may contact the edge 90 of the slot 24. Due to the inclination of theengagement face 78 toward the second leg 30 and the slope of the edge 90of the slot 24, contact between the boss 26 and the edge 90 of the slot24 causes the boss 26 to move to the second stop 92 of the second leg30. Alternatively, the boss 26″ may move substantially in the proximaldirection 15 directly to the second stop 92 of the second leg 30. Ineither case, the spring 44 forces the guard 18 away from the adapter 22until the boss 26′″ contacts the second stop 92 or until further axialmovement of the guard 18 away from the adapter 22 is otherwiseprevented. As shown in FIG. 4B, the locking mechanism 82 then preventsany further relative movement between the guard 18 and the adapter 22.

While the particular Automatic Needle Guard for Medication Pen as hereinshown and disclosed in detail is fully capable of obtaining the objectsand providing the advantages herein before stated, it is to beunderstood that it is merely illustrative of the presently preferredembodiments of the invention and that no limitations are intended to thedetails of construction or design herein shown other than as describedin the appended claims. Further, it is contemplated that the boss andslot cooperating structures may be reversed such that the boss be formedon the guard and the slot be formed in the adapter. Such an embodimentis considered to be an equivalent combination of structure to thespecific embodiment disclosed and claimed herein.

what is claimed is:
 1. A medical device comprising: (a) a body, the bodyhaving a distal end and a proximal end; (b) a needle, the needle havinga distal end and a proximal end, wherein the needle is coupled with thebody; (c) a guard having a distal end and a proximal end, the guarddefining a chamber, wherein the guard is configured to translate axiallyrelative to the body; and (d) a removable shield having a first shieldposition and a second shield position, wherein the removable shield, inthe first shield position, covers the distal end of the needle andprevents the guard from translating relative to the body.
 2. The deviceaccording to claim 1, the device further comprising a spring positionedbetween the guard and the body.
 3. The device according to claim 1,wherein the guard is movable from a first guard position, wherein atleast a portion of the needle extends through an orifice defined by thedistal end of the guard, to a second guard position, wherein the distalend of the needle more fully extends through the orifice relative to thefirst guard position, to a third guard position, wherein the distal endof the needle is substantially retained within the chamber defined bythe guard.
 4. The device according to claim 3, further comprising a lockthat substantially prevents axial movement of the guard relative to thebody in the third guard position.
 5. The device according to claim 1,wherein the removable shield includes at least one radially-extendingrib positioned within the chamber defined by the guard.
 6. The deviceaccording to claim 1, wherein the removable shield includes a first riband a second rib, the first rib opposing the second rib, wherein thefirst rib and the second rib are positioned within the chamber definedby the guard.
 7. The device according to claim 6, wherein an orificedefined by the distal end of the guard includes a first slot and asecond slot sized to accept the first rib and the second ribrespectively.
 8. The device according to claim 1, wherein the secondshield position comprises removing the removable shield such that thedistal end of the needle is exposed and the guard is allowed to moveaxially relative to the body.
 9. A medical device comprising: (a) abody, the body having a distal end and a proximal end; (b) a needle, theneedle having a distal end and a proximal end, wherein the needle iscoupled with the body; (c) a guard having a cylindrical wall, a distalend, and a proximal end, the cylindrical wall defining a chamber,wherein at least a portion of the body is positioned within the chamberand the guard is selectively movable relative to the body; and (d) aremovable shield, wherein at least a portion of the removable shield ispositioned within the chamber defined by the guard such that theremovable shield in the chamber substantially limits axial movement ofthe guard relative to the body.
 10. The device according to claim 9,further comprising a spring positioned between the guard and the body.11. The device according to claim 9, wherein the guard is movable from afirst guard position, wherein at least a portion of the needle extendsthrough an orifice defined by the distal end of the guard, to a secondguard position, wherein the distal end of the needle more fully extendsthrough the orifice relative to the first guard position, to a thirdguard position, wherein the distal end of the needle is substantiallyretained within the chamber defined by the guard.
 12. The deviceaccording to claim 11, further comprising a lock that substantiallyprevents axial movement of the guard relative to the body in the thirdguard position.
 13. The device according to claim 9, wherein theremovable shield includes at least one radially-extending rib positionedwithin the chamber.
 14. The device according to claim 9, wherein theremovable shield includes a first rib and a second rib, the first ribopposing the second rib, wherein the first rib and the second rib arepositioned within the chamber defined by the guard when the shield is ina first shield position.
 15. The device according to claim 9, whereinthe second shield position comprises removing the removable shield suchthat the distal end of the needle is exposed and the guard is allowed tomove axially relative to the body.
 16. A medical device comprising: (a)a body having a distal end and a proximal end; (b) a needle, the needlehaving a distal end and a proximal end, wherein the needle is coupledwith the body; (c) a guard having a cylindrical wall, a distal end, anda proximal end, the cylindrical wall defining a chamber, wherein atleast a portion of the body is positioned within the chamber and theguard is selectively movable relative to the body between a first guardposition, a second guard position, and a third guard position; and (d) aremovable shield, having a first shield position and a second shieldposition, wherein in the first shield position the removable shieldcovers the distal end of the needle and at least a portion of theremovable shield is positioned within the chamber defined by the guardsuch that the removable shield substantially limits axial movement ofthe guard relative to the body, and in the second shield position theremovable shield is removed such that the distal end of the needle isexposed and the guard is axially movable relative to the body.
 17. Thedevice according to claim 16, wherein the first guard position comprisesat least a portion of the needle extending through an orifice defined bythe distal end of the guard, the second guard position comprises thedistal end of the needle extending more fully through the orificerelative to the first guard position, and the third guard positioncomprises substantially retaining the distal end of the needle withinthe chamber defined by the guard.
 18. The device according to claim 16,further comprising a lock that substantially prevents axial movement ofthe guard relative to the body in the third guard position.
 19. Thedevice according to claim 16, wherein the removable shield includes atleast one radially-extending rib positioned within the chamber.
 20. Thedevice according to claim 16, wherein the removable shield includes afirst rib and a second rib, the first rib opposing the second rib,wherein the first rib and the second rib are positioned within thechamber defined by the guard when the shield is in the first shieldposition.